Adsorption of salicylic acid in aqueous solution by a water-compatible hyper-cross-linked resin functionalized with amino-group

摘要

On account of the high toxicity of nitrobenzene, 1,2-dichloroethane was used as solvent. A novel water-compatible hyper-cross-linked resin functionalized with amino-group (denoted as GQ-04) was synthesized to remove salicylic acid (SA) in aqueous solution. The maximum adsorption capacity of SA onto GQ-04 was observed at pH of 1.88. The adsorption capacity increased with the increasing salt concentration. The adsorption kinetic data obeyed the pseudo-second-order rate equation and the adsorption isotherms can be characterized by Freundlich model. The intraparticle diffusion was the main rate-controlling step. The saturated adsorption quantity of SA was up to 119.9 mg·mL-1 according to the dynamic adsorption at 293 K. The resin could be regenerated by the 6 BV mixed solution of 80% ethanol and 0.5 mol/L NaOH. The size matching and hydrogen bonding between GQ-04 and SA and the micropore structure resulted in the larger adsorption capacity in comparison with XAD-4 and H103 resin.